Sorry about the horrible title, didn't now what to say. I'm trying to avoid having to send an IV with every message purely to keep packet sizes down, so I thought of a method to establish a "IV ...
SSL 3.0 and TLS 1.0 used an insecure scheme to generate implicit IVs when encrypting records in CBC mode: They used the last part of the previous record, a value that can be predicted by the attacker. ...
I'm implementing a protocol which needs a 64-bit IV for every encrypted packet. The cipher in use (AES-GCM, more or less as specified in RFC 4106) does not require that these IVs are random, only ...
The message format includes a datetime field in the clear. Is it okay to also use this field (or some hash thereof) as the initialization vector? In this case, CBC is the mode being used.